1. Field of the Invention
The present invention relates to techniques for nesting articles.
2. Description of the Related Art
Nesting devices have been used successfully to reduce the amount of manual labour required to fabricate a variety of articles. Channel members are especially labour intensive since one must be nested into another before they can be stacked efficiently. A common type of channel member is a wall stud which in recent years has seen widespread use in the walls of modem buildings. The wall stud fabricating industry is heavily labour intensive and the risk of repetitive strain injury claims is high, in part due to the need to invert, nest and stack the wall studs. There remains a need for an automatic nesting device that will reduce the labour required for handling channel members. An example of such nesting machines is U.S. Pat. No. 5,456,572 to OVERINGTON which is incorporated herein by reference. The device herein makes use of a pair of paddles to rotate each of a pair of channel members into a vertical position and at the same time cause them to be nested together. Though satisfactory for its intended purpose, this technique requires a relatively complicated structure and will not accommodate certain dimensional variations between channel members.
It is an object of the present invention to provide an improved technique for nesting articles.
Briefly stated, the invention involves a method of nesting a pair of elongate articles, each having a complementary nesting surface, comprising the steps of:
providing an article receiving surface;
delivering a first elongate article to a first ready position on the article receiving surface; the first article having a first near end portion and a first far end portion;
delivering a second elongate article onto the article receiving surface; the second article having a second near end portion and a second far end portion;
arranging the second article so that the second near end portion lies in a second ready position adjacent the first near end portion;
engaging the near end portion of one of the articles independently of the far end portion thereof;
transferring the engaged near end portion relative to the other of the near end portions to initiate nesting thereof; and
manipulating at least one of the articles downstream of the first and second near end portions, to allow the nesting of the articles to continue beyond the first and second near end portions.
In another aspect of the present invention, there is provided a device for nesting a first article and a second article, each having a nesting surface and a number of formations extending outwardly therefrom, the first article having a first near end portion and a first far end portion and the second article having a second near end portion and a second far end portion, comprising:
an article receiving surface;
locating means for locating the first article on the surface at a first ready position;
means for delivering the first and second articles to the article receiving surface with the second near end portion located at a second ready position adjacent the first near end portion;
engaging means for engaging the near end portion of one of the articles independently of the far end portion thereof;
transfer means operable with the engaging means for transferring the engaged near end portion relative to the other of the near end portions, thereby to initiate nesting of the engaged near end portion with the other near end portion; and
manipulating means for manipulating at least one of the articles downstream of the first and second near end portions, to allow nesting of the articles to continue beyond the first and second near end portions.
The present technique also provides for the nesting articles of the type having a nesting surface with a number of formations thereon, comprising the steps of:
locating a first article and a second article side by side, with the nesting surfaces of the first and second articles being oriented in a common ready position, with the first article positioned between the locating means and the second article,
transferring the first article about an axis of rotation from the ready position toward an inverted position;
biasing the second article toward the first article, in order to nest the formations of the second article in the ready position with the formations of the first article in the inverted position, with the formations in staggered relationship.
In still another aspect of the present invention, there is provided a device for nesting articles of the type having a nesting surface with a number of formations thereon, the device comprising:
locating means for locating a first article and a second article side by side, with the nesting surfaces of the first and second articles being oriented in a common ready position, with the first article positioned between the locating means and the second article,
transfer means for transferring the first article about an axis of rotation from the ready position toward an inverted position;
biasing means operable with the transfer means for biasing the second article toward the first article, in order to nest the formations of the second article in the ready position with the formations of the first article in the inverted position, with the formations in staggered relationship.